A bar feeder pushes barstock into a lathe for continuous, unattended production of small turned parts; Swiss-type lathes use a guide bushing for long, slender, high-precision work. The pairing defines high-volume precision turning. Feeders and guide bushings factor into a machine's value and use case.
See every Turning Centers & Lathes in the reference library, by make and model.
How this affects buying and selling: read The Gauge, or value any machine free at The Machine Blue Book.